Palladium-catalyzed arylative benzannulation of 4-alkynyl-3-alkenyl indoles with arylboronic acids to benzo[cd]indoles

A new protocol employing arylative sequential reaction of alkynes with boronic acids in one-pot has been developed to access benzo[cd]indoles as products via carbometalation of alkyne followed by intramolecular Michael addition. The one-pot reaction of 4-alkynyl-3-alkenyl indoles bearing a Michael acceptor at the 3-position with boronic acids catalyzed by palladium/triflic acid furnished the products through intramolecular dearomative-aromatization (benzannulation). [Display omitted]